Portion of a key blade blank



FIG. 1 is a front view of our new design of a portion of a key blade blank;

FIG. 2 is a right side view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a top view thereof; and,

FIG. 5 is a bottom view thereof. 

The ornamental design for a portion of a key blade blank, as shown and described. 